Field of Technology
The present disclosure relates to multi-step methods for melting and refining superalloys and other alloys. The present disclosure also is directed to alloys prepared and refined using the multi-step melting and refining methods described herein, as well as to mill products and manufactured products including the alloys.
Description of the Background of the Technology
Various techniques are known for melting and refining superalloys so that the alloys are suitably free from problematic inclusions, segregation, and other defects. Various emerging technologies will require larger and more massive alloy forms, placing greater demands on existing melting and refining techniques. For example, current melting and refining techniques used to produce superalloys for turbine disk components allow ultrasonic indications to be addressed at intermediate stages during processing of the alloys without significantly impacting final part costs. With the advent of significantly larger turbo machinery such as, for example, the GE90 and GEnx turbine engines, substantially larger superalloy billets with sizes sufficient for very large disk components are required. These superalloy billets may have weights greater than 1000 lbs., and turbine engines in development may require superalloy billets up to 3000 lbs. Existing melting and refining techniques may be incapable of producing superalloy billets of this size on a cost-effective basis due to, for example, substantial yield loss as material that fails ultrasonic inspection and other non-destructive testing is scrapped.
Accordingly, there is a need to develop an improved melting and refining process for producing superalloys and other alloys.